Iowa State University researchers have devised a method to improve the processability of the lignin-based prescursor so that small diameter lignin fiber can be produced, spun, and stretched prior to pyrolysis into carbon fiber. In the proposed method a commonly available solvent plasticizes the lignin to a degree that allows spinning the resulting fiber into a coagulation bath which easily removes the solvent. Since no thermal or oxidative degradation has occurred during processing, the resulting fibers contain a very high concentration of lignin and are therefore relatively consistent in properties.